The subject matter described herein relates generally to hydrocarbon reforming for generating hydrogen, and more particularly, to a system and method for use in monitoring a catalyst and a reformate stream within a catalytic reforming assembly.
Doping of a hydrocarbon, such as methane, with hydrogen generally improves the turndown capability of a gas turbine and enables the turbine to power less than full loads more efficiently. However, often storing and transporting the hydrogen may be difficult, which promotes in-situ generation of hydrogen, i.e. generation of hydrogen at the location of the gas turbine.
One known method used to generate hydrogen involves reforming hydrocarbons, such as methane, using a catalytic reforming assembly. A controlled molar quantity of a hydrocarbon feed stream, such as methane, and a controlled molar quantity of an oxidizer stream, such as oxygen (O2), are channeled over a catalyst to create a hydrogen rich reformate gas stream. However, if the catalyst is not performing efficiently then some oxygen may flow through the system without being catalyzed. Such a condition is referred to as oxygen slip and may cause premature ignition of the reformate gas stream. Generally, catalytic reforming assemblies are equipped with hardware that continuously measures and controls the flow rate of methane and oxidizer to the catalyst. Moreover, one or more spray nozzles are provided to mix the methane and oxidizer upstream of the catalyst in an attempt to control the proper molar proportions of methane and oxidizer to the catalyst to avoid oxygen slip.
The reactivity of a catalyst can degrade over time. Known reformer systems use temperature sensors to determine the temperature of a catalyst as an indicator of the operating effectiveness of the catalyst. In such systems, if the temperature of the catalyst falls below a predetermined threshold, often this is an indication that the reformer system needs maintenance, such as a refreshing or a replacement of the catalyst. Such maintenance often requires shutdown of the reformer system. Other known reformer systems may supplement the catalytic function using a plasma arc, for example, when the temperature of the catalyst falls below the predetermined threshold, or otherwise indicates a decreased performance of the catalytic reforming assembly.